Backround: ok, so about a week ago i noticed that my Veil Tail betta, Knight, was gettin some rips in his tail! i looked at it but there was no black spots,i tryed to post a thread on here (did not work for some odd reason) after that i put off finding a cure. i just showed him his mirrior last night and his abdominal fin tore almost completly in half! so he now ooks like a crown tail and he has an extra torn fin. (ps. he is the only fish in the tank) (pss. i figured out that too much activity tears his fins quicker and sorry i cannot post a picture at this time)

How much and how often are you making water changes and when was the last one?
I have found the best treatment for torn fins is fresh clean dechlorinated water with daily water changes for about 10 days and then regular twice weekly 50% water changes on tanks 6g and less to provide a healthy environment and removing any uneaten food in between water changes.
If you suspect a secondary infection I add aquarium salt 1tsp/gal, IAL or oak leaves, high protein diet along with the daily water changes for 10 day

I agree.. I've been using that method for a while and it works great. My fish always start showing significant improvement in 3-5 days. Water changes are the key.. I don't care what illness it is water changes ALWAYS help in healing.